I love the info on this board and would appreciate some input. I have written a few times about the issues that I have with my 05 Hummer H2. Its pushing water some where but most troubling to me is the 165,xxx miles. I know to most of you that's not a ton of miles but as an old gear head, it drives me nuts. I like to jump in the truck and head down to the FL Keys or to the mountains often so I don't want to think twice about reliability.

I tow nothing with this truck and am not an off roader. Its big and comfortable and fits all my family and my stuff so that's why I purchased it 130,xxx miles ago.

I am considering a GM crate LSA swap or my 1st thought was a LS3 type long block with the ability to go to a super charger and I am not educated enough as to the fun factor between a roots type SC or a centrifugal type SC. I've never driven anything with a LSA or SC so I am not aware of the differences between to two at all. I'm looking for the most fun to drive. I won't say that money is no object but for this project I'm not going to worry about it. Surprising the typical ford F250 diesel would be a plus. I also don't know if a completely NA LS3 with the right cam and intake would fit the bill. I had a Vette with an LS3 that was a rocket ship but knowing what it was built for and what I currently desire are night and day difference.

I have a built 4l65 now that my transmission guy swears will handle what ever I want to throw at it. I don't know if that's a real thing or not but see that GM sells a whole package that includes a 4l65 or 4l80, so I'm not opposed to upgrading if its needed. Although I do not know if my 4l65 is the same electronic wise as what would be required with the LSA package.

Important to me is that I get something that is pretty simple to get tuned and keep tuned. Each will require fuel system upgrades and exhaust upgrades so they are a push to me. I want to retain the dash lights and gauges that are stock unless there is no other way around it. I don't want some radical POS that requires a stall speed and my rpm range is in the 2000 to 3000 rpm range 99% of the time. The truck will never see anything North of 5500 rpms unless I have a tail wind coming down the mountain. Its like driving a vertical piece of plywood at any speed over 70 mph so I have no delusions about it.

I ask these questions here because the off road gang doesn't seem to have as much experience. I don't think a turbo is the right fit for me but I might be wrong there too. The Lq4 that's in it will come out either way.

Thanks for any advice.

Tim

 

The LSA would probably be the most reliable and long lasting with little maintenance needed over its life span. With the LSA you get instant boost and power comes in early and smoothly so it would work well with a heavy vehicle. You also have the benefit of the GM warranty that comes with the engine.

A centrifugal supercharger is basically a belt driven turbo charger, At lower rpm they don't make a lot of boost but will continue to make boost at higher rpms where the roots style is starting to run out of breath. Power is good but doesn't come in as smooth as the LSA.
I'm sure you're going to have others saying something else is a better alternative and they will have some good points. No choice is going to be ideal and there are always pro's and cons of both.

 

Seriously, you WILL need a 4L80E behind the LSA. The 4L65E, if REALLY beefed up, will do the job. For a while. The end game will be a 4L80E.

 

I would go with the LSA over the LS3 + supercharger. The LSA is a stronger block, has oil squirters to keep the pistons cool, has better head gaskets & I think the LSA head is case in a way that reduces porosity. I went with an LSA block for my 416 so maybe I'm LSA biased

If updating to a new LSA or LS3 etc engine and transmission replacing the fuel pump, alternator, water pump & starter as well for better reliability. Likewise, fluid changes for transfer case and differentials. And so forth.​​​​​​

Sounds like a fun upgrade


Regarding miles & GM V8's

[soapbox on]
Very well maintained fuel injected small block Chevy, LT1 and LS engines smile at a quarter million miles

I put 389,500 miles on a 305 SBC in my 91 RS and it ran perfect when LS swapped, also did regular 1300 mile trips in the car right up to the swap. The high mile RS proved more reliable than my 06 Accord with 43,000 miles which stranded me on a 1300 mile trip I have a 250,000+ mile 02 Z28 that does 1300 mile trips. Three friends have 250,000 + mile Chevy trucks with 5.3's. One has a 300,000 + mile truck.[/soapbox off]

​​​​​​

 

I had a Silverado SS that had 165k on it when I sold it, 90k of those miles with a roots SC on it. It still ran strong when I sold it, but I also did an RPM Level 7 transmission (4L65e).

I also had an H2, which had 100k when I sold it. Kept that stock.

I highly recommend an iron block setup with an H2's weight. Especially if you're going to SC it. Depending on how much boost you plan to run, I also like the centrifugal over roots style.

There are plenty of iron block options, but a 6.0 with a forged rotating assy should treat you well if it's built right. If cost is not an issue, go with a Dart LS Next Pro block with 6 bolt heads.

 

There is absolutely NO reason to do that here.

 

Thanks for all the great advice. I've decided to go with a forged iron block. I'll source it from one of the sponsors here with a nice truck cam and then a good set of factory heads and see how it goes. It will give me room to grow in the future and it might be enough of an upgrade due to higher compression and cam to make me happy. I'd be thrilled with 500hp when its all said and done. If I still can't keep up with those dam diesel Fords, then I can add some forced induction at any time.

Question for anyone, is the factory intake on my 05 Hummer the best truck intake to use? I see other truck intakes that appear to be higher and blockier than mine but I don't know what year or model they are. I am fairly certain that my intake is similiar to Dorman # 615-183. I don't see the $1000 Fast truck intake as being worth it to me and would consider head changes to accommodate a better combo. I am only considering the intake change because when I chaged the knock sensors, one of the plastic nipples on the front of the intake was cracked, so I pressed a brass nipple into the intake to get me by. I don't know how it has faired over the last few years.

Thanks again!

Tim

 

If 500HP is all you end up with, a forged bottom end is a huge waste of money. The stock bottom end can easily handle 700HP.

 

Existing engine needs to come out just for my piece of mind. I'm pushing water somewhere and at 165K miles, I think its time. Not much price difference between forged and cast as far as I can tell.

Tim

 

Call WS6store. They will give you the best pricing and great service for whatever you need. You might find the difference between stock cast pieces, which are all you need, and forged rotating assemblies might be more than you think.

 

I'd call Kyle from Thompson Motorsports. He'd steer you in the right direction:

http://www.thompsonmotorsports.net

 

Thank you for the recommendation. We would love the opportunity to help you with this if you are still in need of any motor options. Also to agree with above, Go to the 4l80 and be done with it. The 4l60/65/70 "can" hold power but it will let you down when you need it the most.

 

I don't understand why, at all. No need for an iron block. And with the weight of an H2, why the HELL would you want to run a centri on a vehicle of that weight, that wants to live mainly at 2-3k rpm? Roots and be done with it. Instant torque = instant satisfaction

 

Going to leave this pig alone and toss on a LSA kit. Will I gain anything by changing to square port heads to bump compression up? The kit I'm looking at comes with adapters so it can go on as is. I'll drive it until it dies then get into the short block.

Thanks for all the great info.

Tim

 

So this is the same engine that's pushing water and you're going to throw a blower on it?

Whose LSA kit is it you're going to run?

I wouldn't take compression over 9.5:1 for pump 93 unless you're keeping stock blower speeds. Even the LSA came from the factory at 9.1:1.
Plan on running meth? E85?

 

Water issue came from a bad water pump. It would only leak when cold. No explanation on that one.
I was looking at the kit boost district offers, it looks complete but I am open to suggestions. I'm not looking at changing anything with the blower and would like it to be 93 octane happy. No corn here in FL. I love my H2, just want to throw some fun into it.

Tim

 

That's actually the EXACT one I was going to recommend.

Good to hear it was the water pump and not the head gaskets.

I just got done swapping a "new from GM" LQ9 6.0 and a 6L80E in a friends 2001 2500HD. Had to swap to an Allison Xfer case as well... what fun.
That's the kit he's getting and I'll be doing the install on that as well. It looks like a well thought out kit with everything needed to get up and running.
We'll be going the reman blower though. No need for new. Once they're rebuilt (bearings, oil, isolator) there's nothing to worry about.

The only thing we might do is swap to LS3 heads in place of the 317's he currently has. of course LS9 gaskets are cheap as well. Yet to be determined though.

 

I will go with the reman one as well with the CTSV lid.

Tim